practice of evaluating MemSet's arguments multiple times, except for
the special case of newNode(), where we can assume the argument is
a constant sizeof() operator.
Also, add GetMemoryChunkContext() to mcxt.c's API, in preparation for
fixing recent GEQO breakage.
given any malloc block until something is first allocated in it; but
thereafter, MemoryContextReset won't release that first malloc block.
This preserves the quick-reset property of the original policy, without
forcing 8K to be allocated to every context whether any of it is ever
used or not. Also, remove some more no-longer-needed explicit freeing
during ExecEndPlan.
to make a reasonable attempt at accounting for palloc overhead, not just
the requested size of each memory chunk. Since in many scenarios this
will make for a significant reduction in the amount of space acquired,
partially compensate by doubling the default value of SORT_MEM to 1Mb.
Per discussion in pgsql-general around 9-Jun-2002..
error handling, and simplifies the code that remains. Apparently,
the code that left Berkeley had a whole "error handling subsystem",
which exceptions and whatnot. Since we don't use that anymore,
there's no reason to keep it around.
The regression tests pass with the patch applied. Unless anyone
sees a problem, please apply.
Neil Conway
elog(ERROR) not an Assert trap, since we've downgraded out-of-memory to
elog(ERROR) not a fatal error. Also, change the hard boundary from 256Mb
to 1Gb, just so that anyone who's actually got that much memory to spare
can play with TOAST objects approaching a gigabyte.
in-chunk leaks, overwrite-next-chunk leaks and overwrite block-freeptr leaks.
A in-chunk leak --- if something overwrite space after wanted (via palloc()
size, but it is still inside chunk. For example
x = palloc(12); /* create 16b chunk */
memset(x, '#', 13);
this leak is in the current source total invisible, because chunk is 16b and
leak is in the "align space".
For this feature I add data_size to StandardChunk, and all memory which go
from AllocSetAlloc() is marked as 0x7F.
The MemoryContextCheck() is compiled '#ifdef USE_ASSERT_CHECKING'.
I add this checking to 'tcop/postgres.c' and is active after each backend
query, but it is probably not sufficient, because some MemoryContext exist
only during memory processing --- will good if someone who known where
it is needful (Tom:-) add it for others contexts;
A problem in the current source is that we have still some malloc()
allocation that is not needful and this allocation is total invisible for
all context routines. For example Dllist in backend (pretty dirty it is in
catcache where values in Dllist are palloc-ed, but list is malloc-ed).
--- and BTW. this Dllist design stand in the way for query cache :-)
Tom, if you agree I start replace some mallocs.
BTW. --- Tom, have you idea for across transaction presistent allocation for
SQL functions? (like regex - now it is via malloc)
I almost forget. I add one if() to AllocSetAlloc(), for 'size' that are
greater than ALLOC_BIGCHUNK_LIMIT is not needful check AllocSetFreeIndex(),
because 'fidx' is always 'ALLOCSET_NUM_FREELISTS - 1'. It a little brisk up
allocation for very large chunks. Right?
Karel
for details). It doesn't really do that much yet, since there are no
short-term memory contexts in the executor, but the infrastructure is
in place and long-term contexts are handled reasonably. A few long-
standing bugs have been fixed, such as 'VACUUM; anything' in a single
query string crashing. Also, out-of-memory is now considered a
recoverable ERROR, not FATAL.
Eliminate a large amount of crufty, now-dead code in and around
memory management.
Fix problem with holding off SIGTRAP, SIGSEGV, etc in postmaster and
backend startup.
I have solved some problems with dynamic loading on NT. It is possible
to
run succesfully both trigger and plpgsql regression tests. The patch is
in
the included file "diff".
Dan
Tom Lane
Bruce Momjian
Peter Eisentraut
Jan Wieck
Marc G. Fournier